Delayed action switch mechanism



June 18, 1935. |I E. MCCABE 2,005,195

DELAYED ACTION SWITCH MECHANISM Filed July 3l; 1933 2 Sheets-Sheei lINVENTOR lA E. Nlc CABE ATTORNEY June 18, 1935. l. E. MCCABE DELAYEDACTION SWITCH MECHANISM Filed July 3l, 1933 2 Sheets-Sheet 2 T0 OTHERMAGN ET LSWITCH kOY |R MCCABE BY ATTORNEY INVENTOR Patented June 18,1935 PATENT OFFICE f DELAYED ACTION SWITCH MECHANISM Ira E. McCabe,Chicago, Ill.

Application July 31, 1933, Serial No. 683,037

12 Claims. (Cl. 172-179) This invention relates to improvements inelectric switches andmore particularly to delayed action switchmechanism for the control of `reversing motors such as employed for theopening and closing of doors, valves and the like.

To avoid damage, or unnecessary abuse to reversing motors, or equipmentoperated thereby it is often necessary or desirable to provide a delaybetween the opening of the running circuit and the closing of thereversing circuit and 4 vice versa. 'I'he control of such motors isusually accomplished through remote control switches which open andclose the motor circuits and additional mechanism is required to providethe delay necessary between'the closing of the motor circuit and theoperation of the motor.

It is an object of this invention to provide a switch operatingmechanism for use in connection with such remote control switches. Themechanism is interposed between the source of current and the motor andcaused to function' upon the opening and closing of the remote controlswitch to immediately open the circuit to the motor and thereafter allowa period i'or the slowing up or stopping of the motor before clos'- ing`the reversinglcircuit. It is a further object of this invention toalways provide a positive delay in the breaking of one motor circuit andmaking the reversing circuit, following the operation of the remotecontrol switch, regardless of how rapidly the control switch is causedto operate.

'I'his invention contemplates in the delay switch operating mechanismthe use of a repulsion relay such as disclosed in this applicantsco-pending application, Serial No. 508,185, iiled January l2, 1931,whichV is/ adaptable fory use with veither alternating or direct currentor the relay disclosed in `this applicants co-pending application,Serial No.- 500,747, illed December 8, 1930, which may be of.thetransformer type permitting the use of low voltage'remote controlequipment.

This invention contemplates the employment in connection with the relays'of an electrical resistor in the control circuit. 'I'he resistorcontemplated may be any of the resistance elements, which offers greatresistance to the passage of electric current therethrough when cold,but as its temperature increases, due to the passage of currenttherethrough its resistance decreases un- 4til a large amount of currentis passable. Such elements are `known in the artand one known as Dur-hy,an electric furnace product having as its base silicon carbide withavery highdissocithe switch in closed position.

lEach relay mounts about the vsame leg with the ation temperature, ismanufactured by the Globar Corporation of Niagara Falls, New York.

With these and-other objects in view reference is made to theaccompanying sheets of drawings which illustrate preferred embodiments.of this 5 invention with the understanding that minor detail changesmay be made without departing from the scope thereof.

In the drawings:

Figure -1 is a view in end elevation of one of the relays and switchesoperated thereby employed in this delay action mechanism.

Figure 2 is a view in front elevation of Figure 1.

Figure 3 is s, schematic wiring diagram of the delayed action suchmechanism including two of the relays illustrated in Figures 1 and 2.

Figure 4 is a view in front elevation of a modied form of switchoperating mechanism in which the resistor or delay element is connectedin series with the electro-magnet coil.

Figure 5 is a schematic wiring diagram operating in the same manner asthat shown in Figure 3 and in which only one primary coil is employedand in which the resistor is preferably carried in the shunt switch.

Figure 6v is a view in longitudinal vertical central section through ashunt switch mounting the resistor therein, shown in the open position,with parts shown in side elevation.

yFigure 7 is a view in horizontal section taken on the line l-l ofFigure 6 looking in the direction of the arrows, with parts shown in topplan view.

Figure 8 is a view in side elevation showing The embodiment of thisinvention-as illustrated in the schematic diagram in Figure 3 includesan electric motor M and two relays, such as illustrated in -Figures 1and 2, each of which preferably comprises a rectangular core C withlower stationary primary windings P about one leg of the core which areconnected through binding posts I and 2 to the commercial circuit LL.

primary coil a movable secondary coil S with 45 one terminal of eachsecondary coil connected to the binding post 3 which, in turn, isconnected to the remote control switch RC which switch is adapted toassume a position free of the contacts 4 and l or to 'engage one or theother of the contacts 4 and 5. Each of these contacts are connectedthrough ah'esistor lelement R to the other terminal of the respectivesecondarir coils B. The resistor element is 'preferably of the scribed.

material known as Durhy as hereinabove de-s The remoti, control switchesas shown are prof vided with a neutral position so that having operatedthe motor the desired period thev circuit can be broken thereto.However, reversing motors are obtainable which incorporate switchvmechanisms adapted to switch the motor circuit ward direction. Themotor switch MS on the right hand side of Figure 3 is connected throughbinding post I to binding post l and from thence through the motor andbinding post 2 to the return line to operate the motor in the reversedirection. The motor switches are each carried on one end of operatingarms 8 each pivotally mounted at 8a upon the uncovered leg of theirrespective cores C. Theiopposite ends of the arms 8 are each secured byclips to the bottom of the respective movable secondary coils S and themotorswitches MS are each mounted in the clips upon the arms 8, so thatwhen the secondary coils are in their lowermost position, that isresting upon the top of the respective primary coils, the switches MSwill be open and the circuit therethrough to the motor broken. Each armealso supports a shunt switch SS, preferably of the mercury tube type,which is connected on each side of the resistor R in the secondarycircuit of the movable coil S. This switch SS is kmounted upon the armS, so that when the secondary circuit is open and the coil S is in itslowermost position, this switch SS will also be in the open position. v

The operation of the device shown in Figure 3 is as follows: When theremote control switch RC is moved to engage the contact 4 the secondarycircuit through the coil S is closed through thel resistor R and, as theresistor is cold and its conductivity increases with its increase intemperature, suiicient current will not pass therethrough at first toenergize the relay to repel the secondary coil S. By proportioning theresistor and the number of turns in the windings of the secondary coilthe time required after the closing of the secondary circuit, before theconductivity of the resistor R increases to allow a 'suilicient currentto pass therethrough to repel the secondary coil, may be determined.When the secondary coil is repelled the motor switch MS is tilted toclose thecircuit to the motor, so

. that it will operate in a forward direction. At

the same time the shunt switch SS is closed which shunts out the.resistor R. When it is desired to reverse the motor the remote controlswitch RC is shifted out of engagement with contact I and intoengagement with contactf; thereby opening the circuit through contact 4in the secondary coil S, whereupon it drops and opens the circuit to themotor and closes the circuit through the secondary coil S upon the righthand side through contact 5 and resistor R. The motor cannot operateuntil the conductivity of the resistor R in this circuit allowssufficient current to pass to repel the coil S in that circuit to tiltacceden the motor swimh MS to close the circuit through the motor toreverse its operation.

in this manner a psitive delay is occasioned every time the remotecontrol is operated in either direction for with each operation acircuit is established through a cooled resistor and when the motorswitch is finally closed the resistor is shunted and begins to cool. Asa time interval will always be established by the required period ofmotor operation and the cooling of the resistor is very rapid thenecessary delay will be provided in reversingthe motor even though theremote control is operated'at frequent inter'vals.

The form shown in Figure 4 includes an electro-magnet E which may besubstituted for each oi the relays shown in the schematic wiring diagramin Figure 3,' only the remote control would be placed in one line fromthey source of current supply. AThis form is all high voltagecontrolled. Inthis form an electro-magnet E is mounted on the lower armof a U-shape core '9 having an armature A pivotally mounted at A' uponthe upper arm of the bracket 9.' The armature isA preferably in the formof a bell crank lever pivotally mounted at its apex. The arm AZ e3:-tenring to the right of its pivotal point supports a motor switch,preferably of the mercury tube type, as shown in Figures 2 and 3. Theweight of the, motor" switch so mounted normallyl rotates the armatureout of contact with the'core of the magnet when de-energized. It ispreferable to mount a binding po-st carrying plate B, to 'the right oithe magnet as shown, which remote control switch RC is adapted to closethe commercial circuit from thev source tabinding post id.

'lhe binding post i8 is connected to one end of the windings of theelectro-magnet E. the other end ci which is connected to the bindingpost i2 which in turn is connected through resistor R' to binding 'postH which latter postr is connected to the return commercial line. Theclosing of this circuit vactuates the armature A to'close the motorswitch MS. Binding post i3 is connected to the source of commercialcurrent and to one terminal of the motor switch MS, the other terminalof which is connected to binding post l3nt which in 4turn is connectedto the motor to operate it in the forward direcf tion.

As two of these magnetically operated switches are employed the motorswitch in one is connected with the motor to operate it in the forwarddirection and the motor switch in the other ris connected with :themotor to operate it in the -control switch is closed the circuit isestablished through the resistor R' to the electro-magnet E to close themotor switch. As the resistor is cold there will be delayuntil itstemperature `increases and its resistance decreases sumciently toenergize the magnet to attract its armature ,to close the motor switch.Thereafter as less current is required tomaintain the motor switchclosed the impedance ot the magnet will reduce mounts binding posts I0,Ci, i2, i3 and i3d. The 35 the now of current through the resistor Randl vallow the same to cool.

This type is more or less limited to those applications in which thereversing of the motoris only required at long intervals. Since somecurrent is always passing through the resistor during the period ofmotor operation considerable more time is required to lower thetemperature or the element where it will provide sumcient resistance todelay the reenergization of the magnet. should the circuit thereto bebroken and then again made in rapid succession. When rapid reversing ofthe motor is desired the use of the shunt shown in the other forms ofthis invention provides the delay most satisfactorily.

In the form shown in the schematic Wiring diagram in Figure 5 but onerectangular core C is employed with a stationary primary coil P' securedto the center of the upper leg thereof. 'I'he movable primary coils S'are mounted upon the same leg on either side of the stationary primarycoil P'. The switch`carrying arms 8b are pivotally mounted at 8c to thelower leg oi' the core C and are each secured at their upper ends totheir respective secondary coils. The arms 8b are extended downward onopposite sides of the lower leg to which they are pivoted and the lowerends of each arm support a motor switch MS and a shunt switch SS, asshown, so that the weight of said switches normally maintains the coilsSin contact with the coil P'.

The bindingv post I4 is connected to one side of the source ofcommercial current and alsoflto one winding of the primary coil P', theother wire of which is connected through the binding post I5 to thereturn line commercial current. The binding post I4 is connected throughthe motor switch operated by the left hand coil S to binding post I6 andthence through the motor to operate it in the forward direction to thebinding post I5. The binding post I4 is also connected through the motorswitch MS on the right hand side to the binding post I1 and thencethrough the motor to operate it in reverse direction to binding post I5.

In this form one end of the windings of each oi' the secondary coils Sare connected through their respective shunt switches SS to binding postI8 and from thence to the remote control switch RC'. 'Ihe contact I9adapted to be engaged by the remote control switch is connected to theother end of the winding of the secendary coil upon the right of theprimary coil and the contact 20 adapted to be engaged by the remotecontrol switch is connected to the other end of the secondary coil uponthe left of the primary coil.

In this form the shunt switches SS are identical and each one is amercury tube switch especially constructed to act as both a resistanceelement and as a shunt switch, as shown in Figures 6 and 7. As shown inFigures 6 and 7, the lower terminal 2| is provided with an offsetadapted to engage one end of the resistor element'RZ and the upperterminal 22 is brought down to contact the other end of the resistor R2and hold the same firmly in position between the two terminals at thebottom of the mercury tube switch. By this construction when the remotecontrol switch opens the circuit through a secondary coil, the weight ofthe switches carried thereby returns it to contact with the primary coiland opens both ofsaid switches, so that when the remote control switchre-establishes the circuit through that secondary coil, the currentpasses through the resistor in the open shunt switch causing a delay inthe movement of the secondary coil until the resistor has increasedsumcientlyin temperature to allow suillcient current to passtherethrough to repel said secondary coil, whereupon the motor switchand shunt switches are closed. The closing action of the shunt switchcauses the mercury 23 therein to contact the terminals 2I and 22 tomaintain the secondary coil repelled and the mercury itself not onlyshunts out the resistor R2 but as it submerges the resistor R2 also hasa cooling eiect and accelerates the reduction in temperature of theresistor.

What I claim is: I

1. A motor control including a source of electricity, a motor, means forestablishing a circuit from the source through the motor, a normallyopen switch inthe motor circuit, electrically operated means for closingsaid switch, a remote control switch, means actuated by closing thecontrol switch to establish a circuit through said operating means toclose the motor switch, and means to delay the closing of the motorswitch after the closing of the control switch including a variableelectrical resistor in the control circuit increasing in conductivity asits temperature increases, and means to maintain the motor switch closedand the resistor ineective as long as the control switch remains closed.

2. A delayed action switch mechanism for reversing motors including asource of electricity,- a reversing motor, means i'or establishingindependent circuits from the source to operate the motor in oppositedirections, a normally open motor switch in each independent circuit,electrically operated means for selectively closing a motor switch, aselective remote control switch. means actuated by closing the controlswitch to establish a circuit through the selected operating means toclose the selected motor switch, and means to delay the action of themotor switch operating means upon the closing of the circuittherethrough, whereby after each operation of the selective controlswitch the motor switches remain open for a period allowing the speed ofthe motor to decrease before its operation is reversed including anelectrical resistor increasing in conductivity upon increasingtemperature interposed in the circuit between the control switch andoperating means, and means actuated upon the closing of the motor switchto shunt out the resistor.

3. The structure of claim 2y in which the delay means is interposed ineach circuit between the control switch and the selective motor; switchoperating means. and means actuated upon the closing of the selectedmotor switch to shunt out the resistor in the selected circuit.

4. The structure oi' claim 2 wherein the means for selectively closing amotor switch includes a tween the relay and source, whereby upon theclosing of the control switch the conductivity of the resistor isinsuilicient to operate the relay to close the motor switch until theresistance in the circuit is decreased by the increasing temperature ofthe resistor and thereafter as long as the relay remains energized theresistance of its windings limits the current passing through .theresistor suiliciently to reduce its temperature.

5. A 'delayed "action switch mechanism for reversing-'m ding asourceofelectricity, a reversing-rn means for establishing independent circuitsrom the source to operate the motor in oppos directions, a normally openmotor switch in each independent circuit, electrically operated meansfor selectively closing a motor switch including a repulsion relayhaving a stationary core, a primary coil in circuitv with the sourcefixed thereon, a movable secondary coil, an arm intermediately pivotedupon the ycore attached at one end to the movable coiland mounting amotor switch on-its free end, a selective remote co'r'itrollswit'chfmeans 'actuated upon the 'closing-oi the control switch to establishv acircuit through-l4 the* selected sec-' ondarycoil to repel the coil toclose the selected motor switch, and a normally open shunt Vswitchcarried upon the free end of the 'relay arm having a contained variableelectrical resistor connected in thefsecondarycircuit and having'acontainedv the resistor and connect the inner terminals toA shunt outthe resistor.

'1. 4A motor control including a source of electricity, a motor, meansfor establishing a circuit frorn the source through the motor, anormally open switch in the motor circuit, electrically operated meansfor closing saidswitch, a remote control switch, means actuated byclosing the control switch to establish a circuit through said operatingmeans to close the motor switch, and means to delay the closing of themotor switch after the closing of the control switch including anelectrical resistor increasing in conductivity upon increasingtemperature' interposed in thecircuit between the control.

switch and operating means, and-means actuated upon the closing of themotor switch to shunt out the resistor.

8. A delayed vaction switch mechanism for reversing motors including asource of electricity, a reversing motor, means for establishingindependent circuits from the source to operate the motor in oppositedirections, a normally open motor switch in each independent circuit,electrically operated means for selectively closing a motor switch, aselective remote control switch, means actuated by closing the controlswitch to establish a circuit through the selected operating means toclose the selected motor switch, and means to delay the action of themotor switch operating means upon the closing of the circuittherethrough, whereby after each operation of the selective controlswitch the motor yswitches remain open for a period allowing the'speedof the motor to decrease before its operation is reversed wherein themeans for selectively closing a motor circuit includes,v a repulsionrelay having a stationary core, a primary coil, in circuit with thesource, fixed thereon and a secondary coil movable thereon, an armintermediately pivoted upon said core having one end attached to..themovable coil and the other end mounting a motor switch, and wherein thecontrol switch controls the circuit of the secondary coil.

9. A delayed action switch mechanism for reversing motors including asource of electricity, a reversing motor, means for 'establishingindependent circuits frcm the source to operate the motor in oppositedirections, a normally open motor switch in each independent circuit,electrically operated means for selectively closing a motorv switch, a'selective remote control switch, means actuated by closing the controlswitch to establish a circuit through the selected operating means toclose the selected motor switch, and means to delay the action of themotor switch operating means upon the closing of the circuittherethrough, whereby after each operation c! the selective controlswitch the motor switches remain open `for a period allowing the speedof the motor to decrease before its operation is reversed wherein themeans for selectively closing a motor circuit includes a repulsion relayhaving a stationary core, a primary coil in circuit with the sourcefixed thereon and a movable secondary coil in circuit with the controlswitch, an intermediately'pivoted arm mounted on the core having one endattached to the movable core with the other end mounting a motor switch,and in which the delay means includes a variable electrical resistorinterposed in the secondary circuit.

10. A delayed action switch mechanism for reversing motors including asource of electricity, a reversing motor, means for establishingindependent circuits irom the source to operate the motor in oppositedirections, a normally open motor switch in each independent circuit,electrically operated means for selectively closing a motor switch, Yaselective remote control switch, means actuated by closing the controlswitch to establish a circuit through the selected operating means toclose the selected motor switch, Vand means to delay the action of themotor switch operating means upon the closing o! the circuittherethrough, whereby after each operation oi the selective controlswitch the motor switches remain open for a period allowing the speed ofthe motor to decrease before its operation is reversed wherein the meansfor selectively closing a motor circuit includes a repulsion relayhaving a stationary core, a primary coil in circuit with the sourcefixed thereon, a movable secondary coil in circuit with the controlswitch, an intermediately pivoted arm mounted on the core having one endattached to the movable coil with thev other end mounting a motorswitch, and wherein the delay means includes a variable electricalresistor increasing in conductivity upon increasing temperatureinterposed in the secondary circuit, and wherein a normally open shuntswitch is mounted on the relay arm adjacent the motor switch' and meansupon closing of the shunt switch to establish a shunt circuit about theresistor.y

11. A delayed action switch mechanism for reversing motors including asource of electricity, a reversing motor, means for establishingindependent circuits from the source to operate the motor in oppositedirections, av normally open motor switch in each independent circuit,electrically operated means for selectively closing a motor switch, aselective remote control switch, means actuated by closing the controlswitch to establish a circuit through the selected operating means toclose the selected motor swtich, and

means to delay theaction o! the motor switch opf' eratlng means upon theclosing of the circuit therethrough, whereby after each operation of theselective control switch the motor switches remain open for a periodallowing the speed of the motor to decrease before its operation isreversed wherein the means for selectively closing a motor switchincludes a repulsion relay having a stationary core, a primary coil incircuit with the source fixed thereon and a movable secondary coilmounted on the core on each side of the stationary primary coil, an armpivoted to the core on each side of the primary coil, one end of eacharm attached to the adjacent movable secondary coil with the respectivefree ends mounting a normally open motor switch in the respectiveindependent motor circuits and wherein the control switch controls therespective secondary circuits.

l2. A delayed action switch mechanism for reversing motors including asource of electricity,

a reversing motor, means for establishing independent circuits from thesource to operate the motor in opposite directions, a normally openmotor switch in each independent circuit, electrically operated meansfor selectively closing a motor switch, a selective remote controlswitch, means actuated by closing the control switch to establish acircuit through theselected operating means to close the selecte-d motorswitch, and means to delay the action of the vmotor switch operatingmeans upon the closing of the circuit therethrough, whereby after eachoperation of the selective control switch the motor switches remain openfor a period allowing the speed of the motor to decrease before itsoperation is reversed said delay means including a Variable electricalresistor increasing in conductivity upon increasing temperature, andmeans to maintain the selected motor switch closed and the resistorineffective as long as the control switch closes the said selectedcircuit.

IRA E. MCCABE.

